Thesis Topics

Below is a list of potential thesis topics for students starting in October 2016. We have a number of STFC studentships to use on topics of our choice. These studentships provide full support to UK students.

Students with other funding are welcome to apply for any of the listed topics.

Running Experiments:

ATLAS

The New Energy Frontier

In 2015 the Large Hadron Collider (LHC) started colliding protons together at the record-breaking energy of 13 trillion electronvolts (TeV). This 60 percent increase in collision energy relative to that of 2012 greatly enhances the discovery potential for new heavy particles, such as proposed Dark Matter particles. For us this is a very exciting time, with great opportunities to discover new particles, to test theories and to explore nature at smallest scales with the most powerful accelerator in the world. We now are producing Higgs bosons with double the previous rate, allowing us to enter the "precision era" of the Higgs boson. One of our next jobs is to measure precisely the properties of the newly discovered Higgs boson, to find out whether or not it satisfies the predictions of the Standard Model, and to explore the implications of the new fundamental Higgs force. Over the coming decades, ATLAS expects to gather 100 times more collisions than present, so there’s a huge physics programme of physics ahead of us.

The Oxford ATLAS group has a world-leading physics program with major responsibilities in the areas of:

The ATLAS detector ran successfully during LHC operations and recorded roughly 27 fb-1 of proton-proton collision data which has not all been analysed yet. Major responsibilities of the Oxford ATLAS group include:

New PhD students are expected to work in a combination of the above areas. Each of our students spends one year or more at CERN.
ATLAS D.Phil supervisors are ATLASAcademics [at] physics [dot] ox [dot] ac [dot] uk (Alan Barr, Amanda Cooper-Sarkar, Claire Gwenlan, Chris Hays, Todd Huffman, Cigdem Issever, Richard Nickerson, Georg Viehhauser, Jeff Tseng, Daniela Bortoletto, Ian Shipsey and Tony Weidberg).

Potential graduate students are encouraged to contact supervisors if they have any questions with regard to the thesis topics.

Updated 4.12.15, C Issever

LHCb

B physics and CP violation at the LHC at CERN

LHCb makes precision studies of CP violation in the decay of beauty and charm ('heavy flavour') hadrons at the CERN LHC. LHCb searches for physics beyond the Standard Model by investigating departures from the unitarity of the CKM matrix and checking whether or not this provides a consistent picture of the CP-violation mechanism. These studies can provide valuable insight into the phenomena responsible for matter-antimatter asymmetry in the Universe. The experiment also has high sensitivity to new physics effects by looking for enhanced rates of heavy flavour decays that are extremely rare in the Standard Model, or in unexpected kinematical distributions of these decays.

The LHCb detector has already collected a wealth of data. Major responsibilities of the Oxford group involve the analysis of physics data (CP violation, rare B decays and charm physics), hardware for the Ring Imaging Cherenkov (RICH) and Vertex (VELO) detectors, and working towards an upgraded LHCb detector. The RICH detectors provide particle identification of pions, kaons and protons over the momentum range from 1 to 100 GeV/c, and the VELO reconstructs B-decay vertices to a precision of around 150μm.

A new graduate student would be expected to work on a combination of the following areas:

Undertake a significant LHCb data analysis, towards a study of the physics of CP violation, rare decays, charm physics or central exclusive production. A major physics interest of the Oxford LHCb group is in the measurement of the CKM angle gamma. We are currently analysing data in the family of channels B→ D0 K with the D0 decaying into 2-,3- and 4-body final states. In addition, the group are measuring rare phenomena in the neutral charm system, such as CP violation and mixing. We are also active in searching for very rare beauty and charm decay channels, and are studying the properties of b-baryons. In addition we are pursuing studies in diffractive physics and QCD via central exclusive production, for which the unique forward acceptance of the experiment brings many advantages. A new student could expect to work in any one of the above areas, or develop an alternative analysis effort which is commensurate with the general interests of the group.

Oversee the operation of the high-speed on-detector electronics, data links and data-acquisition for the RICH system, and monitor the performance of the detector and its readout system. Organise the magnetic calibration of the RICH photon detectors and associated data analysis. Maintain the calibration of the RICH system’s performance using real data. Of particular interest is the calibration method of cleanly detecting a background-free sample of K’s and π’s from D*±→ D0 (→K π) π±, and Λ0 → pπ decays.

Monitor the data quality of the VELO detector, and also the opening and closing characteristics of the silicon planes.

Develop hardware snd software for the upgraded LHCb detector. This could include studies of the physics performance, production readiness for the upgraded VELO detector, and its mirco-channel cooling system, and developments in both mechanics and electronics for the upgraded particle identification system (RICH) or novel time-of-flight techniques (TORCH).

T2K

Tokai to Kamioka Neutrino Oscillation Experiment

The Oxford T2K group is eager for new D.Phil students to join. We received our first data in November 2009 and have mostly been taking data since. With the build-up of the neutrino beam intensity, now is an excellent time to join the experiment. For information about the group's activities and potential thesis analysis work, please see our home page at http://www2.physics.ox.ac.uk/research/t2k/thesis-topics

MicroBooNE

The MicroBooNE experiment has built a medium scale (170 tons) LAr detector in the Booster Neutrino Beam at Fermilab. In October 2015, MicroBooNE has started collecting data and will run for at least three years. While MicroBooNE will demonstrate the full potential of these state-of-the-art detectors, its main physics goal is to study an anomalous low-energy excess of events observed by MiniBooNE, a previous experiment at Fermilab. This anomaly could be explained by the presence of a hypothetical sterile neutrino and MicroBooNE will study this intriguing result. In addition, MicroBooNE will also provide crucial neutrino cross-section measurements on Argon, which will be essential for future neutrino projects such as DUNE. Several thesis topics are available within the MicroBooNE group at Oxford on neutrino oscillation physics or neutrino cross-section measurements. Thesis topics have a perfect time scale for a PhD student since the data will be available for analysis during the whole duration of the project and leading to a main physics analyses. This research will allow the student to gain great experience with LAr data (analysis and simulation), which will be extremely important in the future. The student would be expected to travel to Fermilab in the USA for MicroBooNE data taking shifts and on-site work for the collaboration.

Experiments in preparation:

ATLAS Upgrade

High-Luminosity Large Hadron Collider (HL-LHC)

The High-Luminosity Large Hadron Collider (HL-LHC) project will increase the luminosity of proton-proton collisions by a factor of 10 beyond the LHC’s design value. A more powerful LHC enables the observation of rare processes that occur below the current sensitivity level, extends searches for new physics, and allows precision measurements of the Higgs boson and other particles. The HL-LHC is currently expected to begin operations in the second half of 2026, with a nominal levelled instantaneous luminosity of L=7.5×1034cm2s1 corresponding to an average of roughly 140 inelastic pp collisions each beam-crossing. The machine will deliver an integrated luminosity of 3000/fb to the ATLAS experiment over ten years starting in 2025. This is a factor ten greater than the target of 300/fb to be delivered by 2023.

The ATLAS collaboration must replace many subdetectors to take full advantage of this accelerator upgrade. Oxford and the UK are leading the Inner Tracker Upgrade (ITk) in the production of the barrel strip silicon tracker and the forward pixel tracker for the upgraded ATLAS detector.

Precision Higgs Physics at HL-LHC

Simulation of events in the ITk with a pileup of 140

Updated 9.2.16, D Bortoletto

LZ

The nature of dark matter remains one of the biggest unsolved mysteries in modern science. Accordingly, a number of facilities worldwide are in operation or are being designed and commissioned for detecting dark matter particles. The Oxford dark matter group are members of the LZ collaboration, who are designing and constructing a large liquid xenon time projection chamber, aimed to detect interactions from dark matter particles. LZ will be housed in the Davis Campus of the Sanford Underground Research Facility in South Dakota, USA and will inherit the infrastructure and water Cherenkov detector of the presently running LUX experiment. This is a particularly interesting time for being involved in a dark matter search experiment, and especially in LZ, which, due to its size will reach sensitivity that will either lead to dark matter detection or, in the absence of a signal, will eventually be limited by the irreducible neutrino background. For further detail, see http://lz.lbl.gov/ or http://www.sanfordlab.org/.

Possible thesis topics include developing the software and analysis tools needed for science exploitation of LZ data, modelling and simulation of the detector, or participation in the design, construction and commissioning of central instrumentation for LZ.

Neutrino Liquid Argon Experiments

Thesis topics for LAr experiments

Liquid Argon detectors will play a major role in the future of neutrino physics. These high quality image detectors will allow studying neutrino interactions in great details. They have been chosen for the biggest neutrino project ever constructed (The Deep Underground Neutrino Experiment (DUNE)) and will provide the sensitivity required to study some of the big questions of neutrino physics such as the neutrino mass hierarchy and CP violation.

The neutrino Liquid Argon (LAr) group is currently looking to recruit PhD students. The Oxford group is heavily involved in several LAr projects such as MicroBooNE (170 ton LAr detector at Fermilab which started data taking in 2015), DUNE(a future very large scale LAr neutrino experiment in the USA) and local R&D work on optical readout for LAr technology (a test stand is being built at the Rutherford Appleton Laboratory (RAL)). Several thesis topics are available within our group to work on MicroBooNE, DUNE or LAr R&D project.

The DUNE project is very large scale experiment that will be developed in the next years. The student would be expected to participate in studies to help understanding the physics reach of this future experiment as well as simulations to help make design decisions. The study topics within DUNE are vast and would allow the student to gain strong experience in programming, data simulation and analysis.

Whether the student chooses to work on MicroBooNE or DUNE, there would be possibilities to work on the LAr R&D test stand at the RAL, to gain valuable hardware experiment. In this case, the student will be expected to travel to RAL to work on the experimental setup.

SNO+

Neutrino Physics at the SNOLAB facility in Canada

SNO+: Neutrino Physics at the SNOLAB facility in Canada

Some of the most exciting physics to emerge over the last decade has been in the field of neutrino physics. One of the forefront experiments here has been the Sudbury Neutrino Observatory (SNO), based in Canada, which was a recipient of the 2015 Nobel Prize in physics. The SNO group at Oxford have played a leading role in solving the "Solar Neutrino Problem" and clearly demonstrating, for the first time, that neutrinos exists as mixed states which allow them to apparently "oscillate" from one type to another. On the heels of this tremendously successful project, a follow-on experiment, SNO+, is being pursued with a remarkably diverse and interesting range of physics objectives. The main objective of this project is to sensitively search for a very rare process called "neutrinoless double beta decay." An observation of this would both permit a determination of the absolute neutrino masses and would establish that neutrinos act as their own antiparticles, which could have significant consequences for our understanding of the matter/antimatter asymmetry in the universe. This area of study is considered to be of extremely high importance in particle physics and the Oxford group has played a fundamental role in establishing the technique that will be used for this search. In addition, other physics goals include studies of low energy solar neutrinos, oscillations of reactor antineutrinos, searches for non-standard modes of nucleon decay, study of geo-neutrinos generated from within the earth, and to act as an important detector for neutrinos from galactic supernovae. The detector is currently undergoing initial water fill and commissioning. Liquid scintillator will be introduced in 2016 and isotope for neutrinoless double beta decay will be introduced in 2017. The incoming PhD student would participate in development, simulation, calibration, operation, analysis and the production of first results.

JAI and R&D projects

John Adams Institute for Accelerator Science

The John Adams Institute was founded in April 2004 as one of two Institutes of Accelerator Science in the UK. The institute is a joint venture between Oxford University, Royal Holloway, University of London and Imperial College London. The current R&D projects are focused on the area of synergy between laser and plasma physics and accelerators; on research towards novel compact light sources and FELs; on design studies for future colliders and neutrino factories; on development of advanced beam instrumentation and diagnostics; on development of new accelerator techniques for applications in medicine, energy, and other fields of science; and research towards upgrades for existing facilities such as ISIS, Diamond, LHC, and new facilities such as ESS and Future Circular Collider. The institute is developing connections with industry, aiming to render the benefits of accelerator science and technology accessible to society. The Institute also has a vigorous outreach programme. Opportunities in a wide variety of research areas exist, as indicated below.

The sections shown below describe the thesis topics available at JAI in Oxford. For more details about the past projects and about projects available at JAI in RHUL and Imperial, visit this page For further information see this page http://www.adams-institute.ac.uk/training/admissions/ and contact Professor Andrei Seryi (andrei [dot] seryi [at] adams-institute [dot] ac [dot] uk).

Advanced Beam accelerator instrumentation, diagnostics and devices

FONT - The FONT group http://www-pnp.physics.ox.ac.uk/~font/ is the international leader in ultra-fast nanosecond timescale beam feedback systems for future high-energy electron-positron colliders. These feedbacks are mandatory for steering and maintaining colliding beams in all currently conceivable linear collider designs. They are also needed in single-pass electron linacs where a high degree of transverse beam stability is required, such as X-ray FELs. The key elements of the feedback are fast, precision Beam Position Monitor signal processing electronics, fast feedback processors, and ultra-fast high-power drive amplifiers. These components are designed, fabricated and bench-tested in Oxford, and subsequently deployed in beamlines for testing with real electron beams of the appropriate charge and time structure.

We work currently mainly at the Accelerator Test Facility in Tsukuba, Japan, and at the CLIC Test Facility (CTF3) at CERN. The group typically visits Japan 4 times per year, for the purpose of testing our novel feedback systems. We are developing a new phase feed-forward correction system at CTF3 and this is an exciting new project for us. Graduate students play a key role in these beam tests, and there are also opportunities to spend time in Japan, at CERN (Geneva) and SLAC (California), as well as to give posters and papers at international conferences.

We are a young and dynamic research team. Ten D. Phil. theses have been completed or are in progress and our graduates have moved on to jobs at CERN, SLAC (USA), Brookhaven (USA), DESY (Germany) and ESS (Sweden).

The active control of nonlinear, relativistic plasmas its confinement are essential in the development of novel, compact sources of coherent Thz and X-ray radiation, laser-plasma and wake-field accelerators. It has been also proven that plasma assistant techniques to control particle dynamics offer a number of ground-breaking solutions to make conventional devices smaller, more energy, space and cost efficient. Traditional materials cannot always satisfy all the requirements for plasma and electromagnetic field control under complex and sometime extreme conditions. Therefore, development of "dial-a-property" materials, which can be tuned to control and drive different phenomena and responses, is vital for future progress. The theoretical and experimental studies of artificial, periodic lattices which mediate the interaction between relativistic plasmas, and electromagnetic fields are novel recently formed, exciting and rapidly developing research field, which is based on more matured studies into complex, passive behaviour of electromagnetic waves coupled through metamaterials and periodic surface lattices. The objective of the research is to apply specially designed, artificial materials, to develop an understanding of the extreme plasmas behaviour in environment defined by such structures, to learn how to confine and control the plasmas, while actively interacting with it, observing either particle acceleration or coherent radiation in UV and X-ray frequency regions. We apply specially designed, artificial materials, to develop understanding of the extreme plasmas behaviour in environment defined by artificial materials and ability to confine and control the plasmas.

The research suggested is on the understanding of plasma dynamic and evolution inside dielectric vessel having corrugated surface. This will involve the study of excitation of such a structure with external source of radiation with and without plasma. Understanding of structure's resonant properties, including external electromagnetic field coupling and eigenmode formation will be also part of the research. The project may branch out to study such phenomena as Thomson and Compton scattering by electron bunches to observe compact X-ray source of coherent radiation. The different plasma instabilities and possible phenomena like wake-field and plasma beat-wave acceleration should be considered. No, doubt that the system described can be used to observe a compact source coherent THz radiation and such research is also suggested for consideration.

Cherenkov Compact source of coherent radiation based on artificial lattices

The sources of coherent radiation are now playing a tremendous role in research and societal life. They become the most "influential" and important tools in wide range of applications associated with precise measurements, and machining as well as security and healthcare. It is well known fact that several emerging applications ranging from bioscience, medicine, pharmaceuticals, spectroscopy to remote sensing are all being hampered in their development and exploitation by the lack of efficient, high power sources of coherent THz, UV and X-ray radiation. It is our intention to create compact source of coherent radiation based on free electron lasing to bridge the frequencies gap. In our research we consider a collective interaction of electromagnetic radiation with electron beam inside a periodic lattice formed by either periodic fields such as static magnetic field (FEL) or by artificial periodic materials (Cherenkov lasers). The use of the artificial lattices provides control over non-linear and non-stationary processes taking place inside the interaction region allowing new compact state-of-the-art lasers and user facilities for different applications to be developed. Complex, rich, physical phenomena exist in such systems including excitation of Surface Plasmon Polaritons inside the periodic lattice, Super-radiance and Self-Amplified Spontaneous Emission. The understanding of physical phenomena will opens up new horizons to study and develop state-of-the-art, compact THz lasers able to produce single mode, single frequency, multi-watts output power. This is very exciting and challenging subject which is still at its early stage of development with new fundamental results to be expected.

The research suggested is to realise the compact, high-power THz laser driven by a linear accelerator. The THz spectral range presents a long standing problem in source research. This arises from the absence of suitable atomic and molecular transitions which one can exploit for conventional laser action. Also as the wavelength becomes sufficiently small and the periods sufficiently short this makes standard free electron and solid state microwave techniques problematic. Recent research into the concept of 'artificial' materials has shown that they are capable of yielding a wide range of novel, ground-breaking eletromagnetic properties, which can be tailored to the requirements of applications. In some cases it will allow Cherenkov instability to develop converting the kinetic energy of the electron beam to wave field energy. Understanding of the conditions required to observe Cherenkov interaction and realisation of this potential would allow the development of powerful sources using electron beams of moderate energy and power density.

High-Lumi LHC, Future Circular Collider and accelerator applications

The JAI has a number of projects which will advance the state of the art of accelerator science and technology and will create applications of acclerators in various fields. Examples include LHC High Luminosity upgrade, Future Circular Collider Studies, developments of accelerators for medicine and other societal needs, etc. Contact Professor Andrei Seryi for more details (andrei [dot] seryi [at] adams-institute [dot] ac [dot] uk).

Laser-Plasma Accelerators

In a laser wakefield acclerator an intense laser pulse propagating through a plasma excites a trailing plasma wave via the action of the ponderomotive force, which acts to expel electrons from the region of the laser pulse. The longitudinal electric field in this plasma wakefield can be as high as 100 GV / m, more than three orders of magnitude larger than that found in conventional RF accelerators such as those used at CERN. Particles injected into the correct phase of the plasma wave can therefore be accelerated to energies of order 1 GeV in only a few tens of millimetres.

Theoretical and experimental work on plasma accelerators in Oxford is undertaken by a collaboration of research groups in the sub-departments of Particle Physics and Atomic and Laser Physics.

Particle accelerators are the technology driving cutting edge research at the forefront of modern physics. Current accelerators use rf technology to produce high energy particles for collisions but these machines are large and extremely expensive. Recent progress in laser plasma based accelerators has opened the possibility of using such systems as drivers for free electron lasers (FELs) and the JAI is looking at the development of an XUV radiation source capable of generating ultrashort fs XUV pulses using this technology. The aim is to develop a source small enough to be hosted in a university sized laboratory and brings together experitse in laser-driven plasma accelerators available in Professor Simon Hooker's group in the sub-department of Atomic and Laser Physics (http://www.physics.ox.ac.uk/users/hooker/), with the JAI Accelerator Physics expertise, to provide a strong interdisciplinary environment. A PhD project is currently available on the development of such radiation sources. An additional PhD topic will encompass work on plasma acceleration with particular emphasis on advanced beam diagnostics such as Smith-Purcell radiation and other methods.

The JAI also supports active research activity on 3rd and 4th generation light sources. We have established strong links with the Diamond Light Source (http://www.diamond.ac.uk) located at the Harwell Science and Innovation Campus near Didcot and are actively involved in the programmes for the improvement of the performance of the light source, with new innovation optics design and future machine upgrades. A THz source development programme has been set up in collaboration with RHUL. We are also involved in the design and optimisation of a 4th generation light source within the NLS project (http://www.newlightsource.org). Innovation, cost effective solutions are under investigation in collaboration with Diamond and other national laboratories with the aim of proposing a new national facility in the next years.

Non-destructive Beam Diagnostics

The need for single-shot, compact, relatively inexpensive and non-destructive diagnostics capable to determine the electron bunch parameters in dictated by the rapid developments in the field of laser-driven particle acceleration. The capability to define the electron beam spatial and temporal structure is a vital for development of next generation of particle accelerators, colliders and light sources. We aim to develop single short diagnostics exploiting coherent Smith-Purcell, Transition and Diffraction radiations. The technique used for the diagnostics is generic and can be applied to observe compact source of coherent radiation as well as for steering and compression of electron bunches. The analytic theory and computer models are developed at Oxford University. We also design and machine complex periodic structures and targets for further implementation at the different accelerator facilities (SLAC, RAL). Our group has sufficient understanding of the main theoretical and technical issues relating to SP, Transition and Diffraction Radiation to be position as a world leading research group.

The research suggested is on relativistic femtosecond electron beam interaction with complex periodic surface mono and composite structures. The research will involve both theoretical and experimental studies. It will evolve from current understanding of coherent Smith-Purcell radiation to a new level allowing single short compact non-destructive diagnostics to be designed, build and tested. It is expected that the research may split into two branches with one dedicated to bunch diagnostics while another dealing with compact source of coherent radiation. It is expected that during the research the analytical and numerical models will be built and investigated at Oxford University. Also the complex periodic structures and devices based on such lattices will be designed and built using Department of Physics Engineering and Technical facilities. After construction and testing the devices will be implemented on one of the accelerators facilities either at SLAC or RAL.

Intense Hadron Beams R&D

The team lead by Dr Suzie Sheehy is investigating various advanced accelerator physics methods in order to explore the ways to design high current and versatile proton accelerators for scientific, energy, medical or other applications. We in particular study applications of FFAG technique and explore use of Paul trap approach to study nonlinear dynamics in proton accelerators.

Nonlinear beam physics in circular accelerators

The dynamics of charged particle beam in accelerators is a highly interdisciplinary research area crossing electromagnetism, analytical mechanics, and accelerators technology. The application of advanced techniques in nonlinear dynamics opens a number of new applications that extend performance and capabilities of existing machines. The PhD programme focuses on the investigation of beam dynamics in proximity of nonlinear resonances to manipulate the beam phase space distribution and tailor it for new injection and extraction schemes, or novel concepts in advanced radiation sources.

The programme will develop solid theoretical framework as well as advanced computer simulations in nonlinear beam dynamics for leptons. The PhD programme based at CERN however it will have access to experimental shifts at the Diamond Light Source as well as at the European Synchrotron Radiation Facility.

Graduate Academic Programme (GAP)

The GAP brings together all the training available in MPLS departments and comprises an extensive range of courses for graduate research students and postdoctoral researchers, including academic courses, research, teaching, professional skills and career development training.